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Masahiro Abe

Publications and source records attributed to Masahiro Abe.

At least 19 recordsLinked to original sources
PubMed2006

Characterization of Xenopus digits and regenerated limbs of the froglet.

Xenopus has 4 and 5 digits in a forelimb and hindlimb, respectively. It is thought that their limbs and digits develop in Xenopus by mechanisms that are almost conserved from amphibians to higher vertebrates. This is supported by some molecular evidence. The 5'hoxd genes are convenient marker genes for characterizing digits in the chick and mouse. The anteriormost digit is characterized by being hoxd13-positive and hoxd12 (hoxd11)-negative in the chick and mouse. In this study, we revealed that the anteriormost digit of the Xenopus forelimb is hoxd13-positive and hoxd11-positive, that is, a more posterior character than digit I. The order of formation of digit cartilages also suggested that Xenopus forelimb digit identity is II to V, not I to IV. We have also been interested in the relationship between digit identity and shh. The anteriormost digit develops in a shh-independent way. A limb treated with cyclopamine (a shh inhibitor) has a gene expression pattern (hoxd11-negative) similar to that in shh-deficient mice, suggesting that a hindlimb treated with cyclopamine has a digit I character. However, a Xenopus froglet regenerate (spike), which lacks shh expression during its regeneration process, does not have such an expression pattern, being hoxd11-positive. We investigated hoxd11 transcriptions in blastemas that formed in the anteriormost and posteriormost digits, and we found that the blastemas have different hoxd11 expression levels. These findings suggest that the froglet limb blastema does not have a mere digit I character in spite of shh defectiveness and that the froglet limb blastema recognizes its positional differences along the anterior-posterior axis.

Amino Acid Sequence↗
PubMed2006

Cyclooxygenase isozymes are expressed in human myeloma cells but not involved in anti-proliferative effect of cyclooxygenase inhibitors.

Considering possible tumorigenic activity of cyclooxygenase (COX) isozymes in myeloma, we examined expression levels of COX-1 and -2 in seven human myeloma cell lines (ARH-77, IM-9, RPMI-8226, HPC, HS-Sultan, TSPC-1, and U-266). As analyzed by reverse transcriptase-polymerase chain reaction (RT-PCR), all the cell lines constitutively expressed COX-1, while COX-2 levels markedly varied among different cell lines. Induction of COX-2 by phorbol ester was observed in RPMI-8226 and HPC cells. In contrast, COX-2 was constitutively expressed in ARH-77 and IM-9 cells. Moreover, the high expression level of COX-2 protein in ARH-77 cells was verified by Western blotting. Intact cells of ARH-77 converted 14C-labeled arachidonic acid to prostaglandin E2, F2alpha, and D2, and this activity was dose-dependently inhibited by selective COX-2 inhibitors (SC-58125 and NS-398), a non-selective COX inhibitor (indomethacin), and relatively high concentrations of a selective COX-1 inhibitor (SC-560). These COX inhibitors also suppressed the proliferation of ARH-77 cells, but significant suppression was seen only at 100 microM, a much higher concentration than those sufficient for the COX inhibition. Moreover, proliferation of the myeloma cells lacking COX-2 was also suppressed by 100 microM of SC-58125. These results suggested that the anti-proliferative effect of the COX inhibitors is independent of the inhibition of COX-2.

Arachidonic Acid↗
PubMed2006

Gender differences in correlations among cardiovascular risk factors.

BACKGROUND: Although the clustering of a few specific cardiovascular risk factors is known as the metabolic syndrome, sex-specific differences in correlations among risk factors have not been thoroughly examined. OBJECTIVE: The analysis was undertaken to detect gender differences in correlations among cardio-vascular risk factors. METHODS: Correlations among age, body mass index, systolic and diastolic blood pressures, and serum levels of fasting blood sugar (FBS), triglycerides (TG), high- and low-density lipoprotein cholesterol, high-sensitivity C-reactive protein (CRP), and uric acid were analyzed in apparently healthy Japanese men and women with TG<400 mg/dL and FBS<126 mg/dL. RESULTS: Among the 136 men and 136 women examined, the frequency of significant correlations was marginally higher in women than in men: 28/45 correlations versus 17/45 correlations, respectively (P=0.017). Of a total of 45 possible correlations, 5 were marginally or significantly stronger in women, whereas no correlations among these risk factors were marginally or significantly stronger in men (P=0.021). These gender differences were considerably attenuated after adjustment for age. However, a significant sex-specific difference was observed in the correlation between TG and rank transformation of CRP, even after adjustment for age (P<0.01). CONCLUSIONS: Correlations among cardiovascular risk factors were marginally stronger in women than in men. These results suggest that the existence of 1 additional risk factor may increase the risk of cardiovascular disease more steeply in women than in men.

Adult↗
PubMed2006

Bone destruction in multiple myeloma.

Multiple myeloma (MM) is characterized by accumulation of monoclonal plasma cells in the bone marrow and progression of lytic bone lesions. MM cells enhance bone resorption by triggering a coordinated increase in RANK ligand and decrease in osteoprotegerin in the bone marrow. Macrophage inflammatory protein (MIP)-1alpha and (MIP)-1beta are secreted by MM cells, and play a major role in the enhancement of bone resorption by MM cells. Furthermore, the growth and survival of MM cells are enhanced by contact with osteoclasts (OCs) suggesting the presence of a vicious cycle between OCs and MM cells. OCs also enhance angiogenesis in concert with MM cells largely through the cooperative actions of osteopontin from OCs and VEGF from MM cells. The angiogenic effect may further facilitate the vicious cycle between bone destruction and MM cell expansion. In addition, MM cells secrete soluble factor(s) to suppress bone formation. Secreted Frizzled-related protein (sFRP)-2, an inhibitor of Wingless type (Wnt) binding to Frizzled, is produced by most MM cells, and immunodepletion of sFRP-2 abrogates the inhibition of bone formation. Thus, MM cells enhance bone resorption and suppress bone formation to cause destructive bone lesions. Further elucidation of the mechanism of bone destruction by MM may lead to a novel therapeutic approach to prevent bone destruction and tumor growth.

Bone Development↗
PubMed2006

[Bone disease in multiple myeloma and its mechanism].

Multiple myeloma is characterized by accumulation of monoclonal plasma cells in the bone marrow and progression of lytic bone lesions. Myeloma cells enhance bone resorption by triggering a coordinated increase in RANK ligand and decrease in osteoprotegerin in the bone marrow. Macrophage inflammatory protein (MIP)-1alpha and MIP-1beta are secreted by myeloma cells, and play a major role in the enhancement of bone resorption by myeloma cells. Furthermore, the growth and survival of myeloma cells are enhanced by contact with osteoclasts, suggesting the presence of a vicious cycle between bone destruction and myeloma cell expansion. In addition, myeloma cells secrete soluble Wnt inhibitors, dickkopf (Dkk)-1 and secreted Frizzled-related protein (sFRP)-2, to suppress bone formation. Thus, myeloma cells closely interact with bone cells in the bone marrow microenvironment to enhance bone resorption and concomitantly suppress bone formation, which causes the formation of destructive bone lesions and a rapid loss of bone. Disruption of the pathognomonically skewed cellular interactions in myeloma bone marrow microenvironment may ameliorate bone destruction along with myeloma expansion.

Bone Diseases↗
PubMed2005

Malignant B-lymphoid cells with bone lesions express receptor activator of nuclear factor-kappaB ligand and vascular endothelial growth factor to enhance osteoclastogenesis.

PURPOSE: Receptor activator of nuclear factor-kappaB ligand (RANKL) is a key mediator of osteoclastogenesis. Because certain types of tumor cells aberrantly express RANKL, and because bone destruction also develops in B-cell lymphomas of bone origin, we investigated RANKL expression and the mechanisms of osteoclastogenesis in B-lymphoid neoplasms. EXPERIMENTAL DESIGN AND RESULTS: Immunohistochemistry of bone specimens resected from patients with primary B-cell lymphoma of bone with bone destruction revealed that lymphoma cells express RANKL as well as vascular endothelial cell growth factor (VEGF). The tumor cells isolated from the bone specimens enhanced osteoclastogenesis in vitro. In contrast, B-cell lymphoma infiltrating to the bone marrow without bone destruction did not express RANKL. Both RANKL and VEGF were expressed by a portion of B-lymphoid cell lines, including Daudi and IM-9. These RANKL-expressing tumor cells enhanced osteoclastogenesis from RAW264.7 cells and human monocyte-derived preosteoclasts in the absence of stromal cells/osteoblasts in a RANKL-dependent manner. Furthermore, conditioned media from Daudi cells enhanced transmigration of preosteoclasts that was inhibited by anti-VEGF antibody, suggesting that tumor cell-derived VEGF mediates recruitment of osteoclast precursors. Moreover, cocultures of B-lymphoid cell lines with osteoclasts enhanced the growth of B-lymphoid cells. CONCLUSIONS: Some malignant B cells aberrantly express functional RANKL as well as VEGF to enhance osteoclastogenesis. The coexpression of RANKL and VEGF may also contribute to the close cellular interactions with osteoclastic cells, thereby forming a vicious cycle between osteoclastic bone destruction and tumor expansion in bone.

Bone Neoplasms↗
PubMed2005

Induction of HM1.24 peptide-specific cytotoxic T lymphocytes by using peripheral-blood stem-cell harvests in patients with multiple myeloma.

HM1.24 antigen is preferentially overexpressed in multiple myeloma (MM) cells but not in normal cells. To explore the potential of HM1.24 as a target for cellular immunotherapy, we selected 4 HM1.24-derived peptides that possess binding motifs for HLA-A2 or HLA-A24 by using 2 computer-based algorithms. The ability of these peptides to generate cytotoxic T lymphocytes (CTLs) was examined in 20 healthy donors and 6 patients with MM by a reverse immunologic approach. Dendritic cells (DCs) were induced from peripheral-blood mononuclear cells of healthy donors or peripheral-blood stem-cell (PBSC) harvests from patients with MM, and autologous CD8(+) T cells were stimulated with HM1.24 peptide-pulsed DCs. Both interferon-gamma-producing and cytotoxic responses were observed after stimulation with either HM1.24-126 or HM1.24-165 peptides in HLA-A2 or HLA-A24 individuals. The peptide-specific recognition of these CTLs was further confirmed by tetramer assay and cold target inhibition assay. Importantly, HM1.24-specific CTLs were also induced from PBSC harvests from patients with MM and these CTLs were able to kill MM cells in an HLA-restricted manner. These results indicate the existence of functional DCs and HM1.24-specific CTL precursors within PBSC harvests and provide the basis for cellular immunotherapy in combination with autologous PBSC transplantation in MM.

Antigens, CD↗
PubMed2005

Myeloma cells suppress bone formation by secreting a soluble Wnt inhibitor, sFRP-2.

Multiple myeloma (MM) develops devastating bone destruction with enhanced bone resorption and suppressed bone formation. In contrast to enhanced osteoclastogenesis, little is known about the mechanism of impaired bone formation in MM. Because a canonical Wingless-type (Wnt) signaling pathway has recently been shown to play an important role in osteoblast differentiation, we examined whether MM cells affect a canonical Wnt pathway to suppress bone formation. Conditioned media from RPMI8226 and U266 MM cell lines and primary MM cells suppressed in vitro mineralization as well as alkaline phosphatase activity in osteoblasts induced by bone morphogenetic protein 2 (BMP-2). These cell lines constitutively produced a soluble Wnt inhibitor, secreted Frizzled-related protein 2 (sFRP-2), but not other Wnt inhibitors including sFRP-1, sFRP-3, and dickkopf 1 (DKK-1) at the protein level. Most MM cells from patients with advanced bone destructive lesions also expressed sFRP-2. Furthermore, exogenous sFRP-2 suppressed osteoblast differentiation induced by BMP-2, and immunodepletion of sFRP-2 significantly restored mineralized nodule formation in vitro, suggesting a predominant role for MM cell-derived sFRP-2 in the impairment of bone formation by MM. Thus, in addition to enhanced osteolysis, MM cells also suppress bone formation at least in part through an inhibition of the canonical Wnt pathway by secreting sFRP-2.

Animals↗
PubMed2005

Metastatic renal cell carcinoma presenting as multiple pleural tumours.

A 66-year-old man was admitted with dyspnoea. Chest X-ray and chest computed tomography (CT) demonstrated a left-sided pleural effusion and multiple tumours, suggesting malignant mesothelioma in the left pleural space, but there were no pulmonary lesions. However, abdominal CT revealed a right renal tumour. An ultrasonography-guided needle biopsy of the pleural mass provided evidence of metastatic renal cell carcinoma (RCC). The pleural lesions dramatically decreased in size following right radical nephrectomy and subsequent interferon-alpha treatment. While the thorax is a frequently affected site of RCC, sole pleural metastases are rare and are often secondary to lung involvement. Batson's plexus, a network of vertebral valve-less veins with multiple connections, is likely responsible for the contralateral pleural metastases of RCC.

Aged↗
PubMed2005

Two cases of primary pulmonary osteosarcoma.

Two cases of primary pulmonary osteosarcoma are presented. In both cases, chest computed tomography revealed a calcified pulmonary mass and technetium-99m methylene diphosphonate bone scintigraphy showed intense uptake in the pulmonary mass. Primary pulmonary osteosarcoma was suspected on the basis of these radiographic findings. Microscopic examination of tumor specimens obtained by needle biopsy revealed histologic features of osteosarcoma, and this diagnosis was confirmed by postmortem examination of a second specimen in each case. Radiographic and histopathological findings enabled us to diagnose primary pulmonary osteosarcoma, which is one of the rarest types of cancer.

Aged↗
PubMed2005

[Feasibility of long-term outcome prediction in acute myocardial infarction using the discordance between early and delayed image on 123I-BMIPP myocardial scintigraphy].

OBJECTIVES: The feasibility of long-term outcome prediction using BMIPP myocardial scintigraphy was evaluated in cases of acute myocardial infarction. METHODS: BMIPP myocardial scintigraphy was performed on 165 patients with first acute myocardial infarction at the time of discharge from the hospital (average of 27 days after disease on set). Discordance between early and delayed image was checked and its relation to later cardiac events (during the mean follow up period of 64.2 +/- 9.8 months) was analyzed. In 82 of these 165 cases TlCl scintigraphy was simultaneously performed (Tl/BMIPP dual SPECT) to examine mismatch form BMIPP scintigraphy and discordance between early and images. RESULTS: Discordance between early and delayed images was observed in 86 cases (52%). Among patients for whom dual SPECT was performed, mismatch between TlCl and BMIPP scintigraphy was observed in 30 cases (37%). When the relation between mismatch and discordance was analyzed, mismatch was accompanied by washout. The incidence of later cardiac events was significantly higher for cases showing discordance accompanied by washout and cases showing mismatch on dual SPECT scintigraphy than cases without these findings. When multivariate analysis was conducted, involving age, sex, infarction related artery, left ventricular end-diastolic volume index, left ventricular ejection fraction, severity of disturbed fatty acid metabolism, washout and fill-in, washout was identified as an independent predictor of cardiac events. CONCLUSION: Mismatch on Tl/BMIPP dual SPECT is important for predicting long-term prognosis of acute myocardial infarction. Furthermore, washout on BMIPP scintigraphy is also useful as a predictor of cardiac events.

Aged↗
PubMed2004

2D7 diabody bound to the alpha2 domain of HLA class I efficiently induces caspase-independent cell death against malignant and activated lymphoid cells.

A mouse monoclonal antibody (2D7 mAb), which specifically bound to the alpha2 domain of HLA class I, rapidly induces cell aggregation accompanied by weak cytotoxicity against ARH-77 cells, suggesting that 2D7 mAb had a potential for agonist antibody. In order to enhance this cytotoxicity, 2D7 mAb was engineered to be a small bivalent antibody fragment, 2D7 diabody. The resultant 2D7 diabody showed a strong cytotoxicity against ARH-77 cells. As a notable characteristic feature, the lethal effect of 2D7 diabody was quite rapid, mediated by a caspase-independent death pathway. Furthermore, 2D7 diabody also showed cytotoxicity against several leukemia and lymphoma cell lines, and mitogen-activated peripheral blood mononuclear cells (PBMC), but not for normal resting PBMC and adherent cell lines such as HUVEC. These results suggest that 2D7 diabody could be expected as a novel therapeutic antibody for hematological malignancies as well as inflammatory diseases.

Animals↗
PubMed2004

T cells from presensitized donors fail to cause graft-versus-host disease in a pig-to-mouse xenotransplantation model.

BACKGROUND: The ability of T cells from pigs, the most suitable donors for clinical xenotransplantation, to induce graft-versus-host disease (GVHD) and to facilitate hematopoietic cell engraftment in highly disparate xenogeneic recipients remains unclear. In this article, the authors address these questions in a presensitized pig-to-mouse transplantation model using porcine cytokine-transgenic mice. METHODS: Swine donors were presensitized by mouse skin grafting and boosted by the injection of mouse cells after the skin graft was rejected. Porcine peripheral blood mononuclear cells (PBMC) and splenocytes were collected at various times after mouse skin grafting, and their potential to induce GVHD and to facilitate donor hematopoietic cell engraftment in conditioned murine recipients was evaluated. RESULTS: Presensitization of donor pigs resulted in marked enhancement of anti-mouse responses, as reflected in augmented anti-mouse mixed lymphocyte responses, cell-mediated cytotoxicity, and antibody production. However, injection of high numbers of PBMC and splenocytes (>1 x 10(8)) with bone marrow cells from the presensitized pigs failed to induce detectable GVHD or long-term chimerism in mice that were treated with depleting anti-T-cell and natural killer cell antibodies, cobra venom factor, medronate-liposomes, and 4 Gy of whole-body and 7 Gy of thymic irradiation. Histologic analysis revealed no mononuclear cell infiltration or GVHD-associated lesions in the liver, intestine, lungs, or skin of the mouse recipients. Furthermore, the recipient mice had no detectable T cells or anti-pig immunoglobulin G antibodies in the blood by 6 weeks after injection of porcine cells. CONCLUSION: These results demonstrate that porcine T-cell function is severely impaired in the xenogeneic murine microenvironment.

Animals↗
PubMed2004

Osteoclasts enhance myeloma cell growth and survival via cell-cell contact: a vicious cycle between bone destruction and myeloma expansion.

Multiple myeloma (MM) expands in the bone marrow and causes devastating bone destruction by enhancing osteoclastic bone resorption in its vicinity, suggesting a close interaction between MM cells and osteoclasts (OCs). Here, we show that peripheral blood mononuclear cell-derived OCs enhanced growth and survival of primary MM cells as well as MM cell lines more potently than stromal cells, and that OCs protected MM cells from apoptosis induced by serum depletion or doxorubicin. OCs produced osteopontin (OPN) and interleukin 6 (IL-6), and adhesion of MM cells to OCs increased IL-6 production from OCs. In addition, IL-6 and OPN in combination enhanced MM cell growth and survival. However, the effects of OCs on MM cell growth and survival were only partially suppressed by a simultaneous addition of anti-IL-6 and anti-OPN antibodies and were completely abrogated by inhibition of cellular contact between MM cells and OCs. These results demonstrate that OCs enhance MM cell growth and survival through a cell-cell contact-mediated mechanism that is partially dependent on IL-6 and OPN. It is suggested that interactions of MM cells with OCs augment MM growth and survival and, thereby, form a vicious cycle, leading to extensive bone destruction and MM cell expansion.

Animals↗
PubMed2004

Ability of myeloma cells to secrete macrophage inflammatory protein (MIP)-1alpha and MIP-1beta correlates with lytic bone lesions in patients with multiple myeloma.

Macrophage inflammatory protein (MIP)-1alpha and MIP-1beta have been identified as candidates for multiple myeloma (MM)-derived bone-resorbing factors. To validate the clinical relevance of these observations, we investigated correlations between the ability of MM cells to secrete these chemokines and the extent of MM bone lesions as well as levels of biochemical bone markers in patients with MM. Patients with multiple bone lesions exhibited higher MIP-1alpha and MIP-1beta secretion from MM cells along with elevated urinary deoxypyridinoline (Dpd), without significant elevation of serum bone-specific alkaline phosphatase (BALP) or osteocalcin compared with those with minimal bone lesions. MIP-1alpha and MIP-1beta levels correlated positively with urinary Dpd and serum BALP but not with serum osteocalcin. These results provide further evidence for a causal role of MIP-1alpha and MIP-1beta in the development of lytic bone lesions, and suggest that MM cells suppress osteoblastic bone formation to cause an imbalance of bone turnover and development of destructive bone lesions.

Aged↗
PubMed2004

beta6 integrin is up-regulated in chronic renal allograft dysfunction.

Up-regulation of beta6 integrin, which is indispensable to the activation of transforming growth factor-beta1 (TGF-beta1), was investigated in chronic renal allograft dysfunction (CAD). A total of 103 renal biopsy samples (normal, 10; acute rejection, 30; CAD, 63) were immunohistochemically evaluated for expression of TGF-beta1 and beta6 integrin. No TGF-beta1 or -beta6 integrin was detected in normal kidney, but both TGF-beta1 and -beta6 integrin reactivity were observed in the distal tubules in acute rejection, and even greater reactivity was observed in the distal tubules in the CAD samples. Semiquantitative analysis revealed that the reactivity of TGF-beta1 and -beta6 integrin was significantly greater in the CAD kidney than in the normal kidney and the kidney in acute rejection. The results suggest that beta6 integrin as well as TGF-beta1 is up-regulated in CAD and that it may serve as an alternative target for the treatment for CAD.

Acute Disease↗